Box wall fasteners

ABSTRACT

A box which can be injection molded flat, erected in the field, and when empty knocked down for return shipment. Features include improved structure for holding the parts assembled and for withstanding the stresses of handling, shipping and storage.

llmted States Patent 1191 1111 3,858,745 Eloyd Jan. 7, 1975 [54] BOX WALL FASTENERS 3,472,722 11/1969 Falcone et al. 229/30 x [75] Inventor: Harold S. Cloyd, Erie, Pa. [73] Assignee: Nosco Plastics, Inc., Erie, Pa. Primary Efamifler wmiam Price 1 Assistant lzxammerSteven M. Pollard Flledi g- 23, 1973 Attorney, Agent, or FirmRalph Hammar [21] Appl. No.: 390,920

521 US. Cl. 220/7, 220/60 R [57] ABSTRACT lnt. A box which can be JCCUOH molded flat, erected 1n [58] held o Search 220/7 229/45 the field, and when empty knocked down for return 229/DIG' 8 shipment. Features include improved structure for holding the parts assembled and for withstanding the [56] References C'ted stresses of handling, shipping and storage.

UNITED STATES PATENTS Herbert 220/60 R 6 Claims, 19 Drawing Figures PATENTEU JAN 7' SHEET 2 OF 2 FIG, 12

FIG. /6

FiGq/9 FIG. l8

BOX WALL FASTENERS This invention is a box injection molded flat as a single piece of flexible thermoplastic (polyethylene, polypropylene, etc.) having bottom, top, side and end panels hinged together. The box is erected by folding or swinging the panels into position and connecting adjacent panels by fasteners which tighten under the stresses encountered during handling, shipping and storage. The side and end panels have feet which transmit the gravity load and thereby take the load off the hinges. The fasteners are easily released to permit return of the box to the flat state to reduce the shipping charges for returning empty containers. The fasteners may also fasten internal partitions.

In the drawing, FIG. 1 is a diagrammatic plan view of a preferred form of blank from which the box is erected;

FIGS. 2, 3 and 4 are enlarged sections on lines 2-2, 3-3 and 4-4 of FIG. 1;

FIG. 5 is a section through one of the fasteners which hold the sides and ends of the box together, the fastener being shown in the assembled or locking position;

FIGS. 6 and 7 are corresponding sections of the individual parts of the FIG. 5 fastener on lines 6-6 and 7-7 of FIG. 1;

FIG. 8 is a sectional view of a fastener suitable for securing an internal partition'to a wall of the box;

FIG. 9 is a plan view of a portion of a panel wall containing the tabs forming part of the FIG. 8 fastener;

FIG. 10 is a side elevation of two boxes stacked one on top of the other;

FIG. 11 is a fragmentary view showing the structure for transmitting load from anupper container to the next lower container in a stack;

FIG. 12 is a top plan view of the adjacent edges of the cover of the box;

FIGS. 13 and 14 are sections on lines 13-13 and 14-14 of FIG. 12;

FIG. 15 is a section on line 15-15 of FIG. 10;

FIG. 16 is a diagrammatic plan view of a modified form of blank;

FIG. 17 is an enlarged section on line 17-17 of FIG. 16;

FIG. 18 is a similar section with the fastener in the locking position; and

FIG. 19 is a side elevation of the fastener in the locking position.

The blank for the FIGS. 1-15 box is molded flat as shown in FIG. 1 and comprises a bottom wall 1, side walls 2, 3, end walls 4, 5, and a top wall or cover 6, 6a. The terms bottom, top, side and end are used to identify the walls in the particular structure and are not limitations. Each of these walls consists of a single, generally flat, plastic panel which may be imperforate, as shown, or which may contain openings or perforations for ventilation or for reducing the amount of material required. The panels may have walls of uniform thickness, as shown, or may be ribbed on one or both surfaces to increase the structural rigidity. The inner surfaces of the panels may be smooth, as shown, or may have any other surface treatment desired. None of these modifications affect the basic simplicity of molding the blank. While the side and end panels are shown as rectangular, other polygonal shapes which can be folded, e.g. trapezoidal, may be used. The rectangular panels result in a container with all walls at right angles to each other. Non-rectangular panels can result in some walls which are not at right angles to adjacent walls.

The side and end panels 2-5 are hinged to adjacent edges of the bottom panel 1. The top panel or cover is in two sections 6, 6a, each hinged to the adjacent edge of one of the end and side panels, for example the panels 2, 3 as shown in FIG. 3. The hinges as shown in FIGS. 2 and 3 consist of weakened or thin flexing sections 7 which have sufficient flexibility to permit required hinging of the panels from the flat position shown in FIGS. 1, 2 and 3 to the erected position shown in FIGS. 4 and 10. The outer surface of each of the bottom, side and end panels is bordered by outstanding peripheral ribs 8 which rigidify the edges of the panels. As shown in FIG. 2, the hinges 7 are arranged between adjacent ribs 8.

The cover sections 6 and 6a do not need ribs on the edges 60, 6d which meet in the closed position as shown in FIG. 12, although such ribs could be used. The other three edges of the cover sections have depending ribs 8a as shown in FIG. 3. The edges 60, 6d of cover section 6 have interlocking projections 6e and openings or recesses 6f which dovetail in the closed position of the cover and tie the cover sections together. The mating edges of the projections and recesses 6e, 6f may have a wedge or equivalent fit (FIG. 14) to prevent accidental displacement. A stop 6g on one of the cover sections (e.g. 6) limits penetration of the projections 6e and thereby prevents pushing the projection through the openings 6f. When the projections and openings are engaged, movement of the cover sections 6, 6a relative to each other is prevented. Also, the cover sections when interlocked resist deflection or movement of the wall sections 2, 3 to which the cover sections are hinged.

At the lower edge of each of the side and end panels 2-5 inclusive are integral projecting feet 9 which project from the lower edges of the panels a distance substantially equal to the projection of the peripheral ribs 8. Each of the feet is coplanar with its panel and as molded is coplanar with the bottom panel 1. When the panels are swung to the erected position as shown in FIG. 4, the lower edge 10 of each of the feet 9 is in the same plane as the lower edges 11 of the peripheral ribs 8 on the bottom panel 1. This means that load on the bottom panel 1 is transmitted from the bottom panel to the lower edges 11 of its peripheral ribs 8 and load on the side and end panels such as would be transmitted from upper to lower boxes when boxes are stacked one on top of the other as shown in FIG. 10 is transmitted directly from the side and end panels to the feet. To insure direct transmission of load to the feet 9 vertical ribs 9a, 9b are molded integral with the side and end panels and have upper ends 9a, 9d integral with the ribs 8 at the top of the panels and lower ends 9e, 9fintegral with the feet as shown in FIGS. 4, 10, 11 and 15. This eliminates all possible loading stress on the hinges 7.

In order to accomodate the feet 9, each of the edges of the bottom panel 1 is notches as indicated at 12 to receive the feet of the adjacent side or end panel as the case may be. Each foot 9 and each notch 12 interrupts the hinge section 7. In the particular construction shown in FIG. 1 where there are two supporting feet 9 for each of the side and end panels, there are three hinge sections 7 between each of the side and end panels and the adjacent edge of the bottom panel.

When the side panels 2, 3 and the end panels 4, 5 are swung to the erected position at right angles to the inner surface 13 of the bottom panel 1, outer surface 13a on the vertical ribs 8 of the side panels register with and abut surfaces 14 on projections 15 of the end panels, and the panels are fastened in that position by tabs or projections 16 on the side panels which are received in slots 17 in the end panels. As shown in FIG. 5, each of the tabs 16 is a direct extension of the walls of the associated side panel 3 (or2). The projections 16 are of generally rectangular shape and are spaced apart so as to register the erected position with the slots 17 in the end panels 4, 5. Each projection 16 terminates in a cam faced head 18 having on one side a locking shoulder 19 which engages a detent surface 20 on the end panel as shown in FIG. 5. The other side of the head 18 has an inclined locking surface 21 which in the engaged position shown in FIG. 5 engages the end surface 22 of flexible tab 23 in the end panel. In the assembly, the side panel 3 (or 2) is first swung to the upright position at right angles to the bottom panel 1 and the end panel 4 (or 5) is then swung to the upright position. As the end panel approaches the upright position, the projections 16 enter the slots 17 and the cam faced heads 18 push the flexible tabs 23 outward. The flexible tabs 16 are themselves bent or cammed as the heads 18 enter the slots. Upon being fully received in the slots 17, the locking shoulders 19 on the projections 16 snap over the locking shoulders 20 and the ends 22 of the tabs 23 seat against locking shoulders 21. In this position tension forces tending to pull the tabs 16 out of the slots 17 merely result in tighter engagement of the locking shoulders 19, 21 with the shoulders 20, 22. The width of the slots 17 is less than the thickness of the projections 16. The surface 20a of the stop 20 and the end surface 22 of the tab cooperate to center the projections 16 in the slots 17. Compression forces tending to force the tabs further into the slots 17 are resisted by engagement of the surfaces 13a, 14 and by engagement of stops 24 with the inner surfaces of the end panels 4, 5. In the locked position, the abutting surfaces of the end and side panels are rigidified by the peripheral ribs 8. The resultant connection between the side and end panels is capable of withstanding all of the stresses encountered during handling, shipping and storage. There is no way that the tabs 16 can accidentally pop out of the slots 17.

To disassemble the box and return it to the flat condition of FIG. 1, it is only necessary to pry the tabs 16 clear of the locking shoulders 21, after which the side and end panels may be readily separated.

In some cases the erected box may be an open topped container, in which case the cover or top panel sections 6, 6a will be omitted. After erection of the side and end panels, the cover sections are swung over the top of the container and locked in place by interlocking projections and openings 6e, 6f. The projected area of the cover 6, 6a as shown in FIG. 1 is larger than the projected area of the bottom panel 1 by an amount equal to the projection of the peripheral ribs 8 on the side and end walls. In the assembled position as shown in FIG. 10 the cover 6, 6a accordingly registers with the outer surface of the erected container. The lower ends of the feet 9 and of the associated ribs 9a, 9b are notched as shown at 9g in FIG. 11 so as to be received within the peripheral ribs 8a of the cover 6, 6a. This centers the boxes in the stack. When stacked one on top of the other, the gravity load from an upper container is transferred to its bottom panel and from the bottom panel to the cover 6, 6a of the next lower container which in turn transmits the load to the upper edges of the side and end panels of said next lower container. The load of upper containers in a stack accordingly is received by the side and end panels of lower containers which transmit the received load through the feet 9. This means that the side and end panels of a lower container in a stack must carry all of the load of containers above it in the stack.

FIGS. 8 and 9 show a modification of the fastener construction of FIGS. 5, 6 and 7 which is of particular utility in fastening an internal partition 25 to a wall 26 of a side or end panel 27. For this purpose, the wall 26 is provided with two flexible tabs 28, 29 spaced apart by a slot 30 and the partition 25 is provided with a flexible projection 31 of greater thickness than the width of the slot 30 and having a cam faced head 32 received in the slot 30 and having stops 33 which engage the wall 26 to positively limit the penetration of the projection 31 into the slot 30. In the fully engaged position (FIG. 8), the stops 33 are seated against the surface 26 of the panel 27 and locking surfaces 34, 35 on the under side of the head 32 are engaged with end surfaces 36, 37 of the tabs 28, 29. As with the fastener of FIGS. 5, 6 and 7, tension forces in the direction to pull the projection 31 out of the slot 30 merely results in tighter engagement of the locking surface 34, 35 with the end surfaces 36, 37 of the tabs. Forces in the opposite or compression direction are positively resisted by the stops 33. Accordingly, stresses occurring during service cannot dislodge the connection between the partition 25 and the panel 27. However, by prying one of the tabs 28 or 29 clear of its associated locking projection 34 or 35, the partition 25 may be readily separated from the panel. While only one of the fastening connections is shown between the partition 25 and the panel 27, in normal practice there would be several of these fastening projections for each partition. By the use of such partitions, it is possible to make a bottle case with a wide variety of partitions which can be selected in accordance with the product demand. For example, the same basic case could be partitioned for individual bottlesor for 6-packs or for 8-packs, etc.

The box of FIGS. 16-19 inclusive is generally similar to the previously described box and differs primarily in the structure for holding the side and end panels together.

The blank from which the box is made has a bottom wall 38 to which are hinged side walls 39, 40 and end walls 41, 42 by flexure hinges 43 of the same construction as the hinges 7. The side and end walls each have coplanar feet 44 of the same construction as the feet 9 which are received in notches 45 in the bottom wall in the as molded position shown in FIG. 16. When the end and side walls are swung upward to a position at right angles to the bottom wall 38, the feet 44 swing downward at right angles to the bottom wall into load carrying position. The parts so far described correspond to the previously described construction and, therefore, are only diagrammatically illustrated in view of that disclosure. The optional cover is also not illustrated.

The side walls 41, 42 have outwardly extending catches 46 each with a hook end 47 and an inclined locking face 48 which is received in an opening or recess 49 in the end wall and locks against an inclined surface 50 on the edge 51 of the opening 49 nearest the catch. The catches are integrally hinged to the edges of the side walls by flexure hinge sections 52. The mid sections of the catches are arched as shown at 53 so that when the catches are in position for assembly an inward pressure on the arch as indicated by arrow 54 will cause an outward or spreading movement in the direction of the hook end 47 in the direction of arrow 55.

In the assembly, the end walls 39, 40 are first swung to an upright position. The side walls 41, 42 are then swung up against the end walls with ribs 56 against the inner faces 57 of the end walls as shown in FIG. 18. Now, the catches 46 are pivoted toward the openings 49 and the center of the arch section 53 is pushed inward in a direction of arrow 54, thereby causing the hook end 47 to move upward and be received in the underlying opening 49, they snap in place and establish a locking connection between the inclined surfaces 48 and 50. The catches are protected while in the locked position by peripheral ribs 58 surrounding the sides and hook end of the catches 46. The catches provide a secure attachment of the end and side panels. Outward forces exerted on the inner surfaces of the side and end panels load the catches 46 in tension and bring the inclined surfaces 48 and 50 into tighter engagement. Inward forces exerted on the side and end panels are taken in part by the internal ribs 56 and in part by flexure of the panels which in turn tends to bring the locking faces 48 and 50 into tighter engagement. To release the catches, it is only necessary to apply a force to the hook ends 47 as indicated by arrow 59 to easily move the hook ends clear of the locking surface 50.

Because the box is so easily assembled and disassembled, it is adapted to the transport of goods. After unloading the goods at the destination, the box may be easily returned to the flat condition of FIG. 16 so that less space will be required for returning the box for reloading.

What is claimed is:

l. A box comprising first and second panels transverse to each other, the first panel having an edge transverse to and abutting a surface of the second panel, said first panel edge having a flexible projection with a cam faced head extending through to the opposite surface of the second panel, said second panel having a slot receiving the projection and a tab with a free end at one side of the slot and with the opposite end of the tab joined to said second panel and the sides of the tab free to deflect relative to said second panel, said head extending through said slot and deflecting said tab, a stop on said opposite surface of said second panel, a shoulder on one side of the head engaging said first end of the tab with the tab in the deflected position, and a shoulder on the opposite side of the head engaging said stop.

2. The box of claim 1 in which said stop comprises another tab like the first tab with its free end presented to the opposite side of the slot.

3. The box of claim 2 in which said first panel is a partition.

4. The box of claim 1 in which said first panel is a partition.

5. The box of claim 1 in which said stop is on a rib on said opposite surface of said second panel.

6. The box of claim 5 in which said flexible projection is held against said rib by said tab. =l= 

1. A box comprising first and second panels transverse to each other, the first panel having an edge transverse to and abutting a surface of the second panel, said first panel edge having a flexible projection with a cam faced head extending through to the opposite surface of the second panel, said second panel having a slot receiving the projection and a tab with a free end at one side of the slot and with the opposite end of the tab joined to said second panel and the sides of the tab free to deflect relative to said second panel, said head extending through said slot and deflecting said tab, a stop on said opposite surface of said second panel, a shoulder on one side of the head engaging said first end of the tab with the tab in the deflected position, and a shoulder on the opposite side of the head engaging said stop.
 2. The box of claim 1 in which said stop comprises another tab like the first tab with its free end presented to the opposite side of the slot.
 3. The box of claim 2 in which said first panel is a partition.
 4. The box of claim 1 in which said first panel is a partition.
 5. The box of claim 1 in which said stop is on a rib on said opposite surface of said second panel.
 6. The box of claim 5 in which said flexible projection is held against said rib by said tab. 